Children with specific language impairment (SLI) have difficulty performing tasks involving verbal short-term memory. The purpose of this proposed study is to obtain more specific information on the underlying processes of working memory difficulties in children with SLI. Our goal is to examine the contributions of attentional capacity and the long-term lexicon to working memory performance in children with SLI, in their age- matched, and in their language-matched peers. Previous data from simple working memory tasks showed no significant differences between children with typical development and SLI on articulation rate, encoding, and rehearsal. In more complex working memory tasks (e.g., when word repetition and sentence comprehension are combined) children with SLI perform more poorly than their age-matched peers The long-term lexicon seems to play a critical role in working memory performance. Furthermore, there is an interaction between working memory, attention and the lexicon. If we enhance the contribution of the lexicon in maintaining words, then the attentional requirements for retaining these words in working memory will decrease. Thus, more attention can be focused on the recall processes. The results of children's working memory performances will be compared in four behavioral tasks, including nonword repetition and listening span, under different conditions to examine the effects of attention and the long-term lexicon on working memory performance.